Micrometer



mwmn

ML, 27, W%, E. 1.. FBLLHSCHAFSKE MICROMETER Filed- Jan. 4-, 1936INVENTOR ATTORNEYS Patented Oct. 2'7, 1936 UNITED STATES PATENT OFFICE 2Claims.

This invention relates to micrometers, and has for the primary objectthe provision of a device of this character for accurately measuringinternal diameters such as cylinder walls or any other device wherein anopening is provided and due to its construction a person may readilymeasure the distance between opposite walls with the handle of thedevice arranged approximately centrally of the opening and protrudingfrom the latter whereby the device may be conveniently adjusted with thehands of the person located outwardly of the opening.

With these and other objects in View, this invention consists in certainnovel features of. construction, combination and arrangement of parts tobe hereinafter more fully described and claimed.

For a complete understanding of my invention, reference is to be had tothe following description and accompanying drawing, in which Figure 1 isa side elevation illustrating a micrometer constructed in accordancewith my invention.

Figure 2 is a vertical sectional view illustrating the same.

Figure 3 is a sectional view taken on the line 3--3 of Figure 2.

Figure 4 is a plan View showing one of the spirally threaded discsemployed in the operating means of the micrometer.

Figure 5 is a plan view illustrating another spirally threaded disc.

Figure 6 is a perspective view showing guide plates.

Figure '7 is a perspective View showing one of the adjusting members towhich a feeler is removably secured.

Referring in detail to the drawing, the numeral l indicates a tubularhandle of any desired length and has one end formed on a head or housing2 including an annular wall 3 and end walls 4 and 5. The end wall 4 isintegral with the handle I and also with the annular wall 3. The endwall 5 is removably secured to the annular wall 3. A shaft 6 isjournaled in the handle I with one end protruding into the head orhousing 2 and the opposite end extends outwardly of the handle and hasdetachably secured thereto a thimble or finger piece I. The thimble orfinger piece is of tubular formation and is journaled on the handle Iand is provided at one end with a scale 8. The scale operates inconjunction with a marking 9 on the handle and said marking parallels aslot l0 formed in the handle and opens outwardly through one end of thehandle being normally closed by the thimble or finger piece. Feedthreads II are formed on the shaft and have threaded thereto a feed nutif provided with an indicator l3 operating through the slot I0 and inconjunction with a scale M arranged in conjunction with the marking 9.

Discs I5 are secured to the shaft 6 and are located in the head orhousing 2 and spaced from one an other and have formed upon theiropposing faces spirally formed threads I6. The threads l6 of one of thediscs are of right hand formation while the threads of the other discare of left hand formation. slidably supported between the opposingfaces of the discs are feeler supporting elements ll having their innerends of substantially rectangular shape, as shown at [8, and provided onopposite faces thereof with threads IE to match the threads I6 of thediscs I5. The smooth faces of the rectangular shaped portions areengaged by supporting discs or plates 20 removably secured tothe housingor head. The feeler supporting elements operate through oppositelyarranged openings formed in the annular wall 3 of the head or casing andare socketed to removably receive feelers 2|. These feelers may be ofany desired length and are moved inwardly and outwardly with respect tothe head by the rotation of the shaft 6 and the latter is rotated by thefinger piece or thimble l. The handle I being located centrally of thehead or casing permits the latter to be readily positioned with anopening and by rotating the finger piece or thimble from a pointexteriorly .of the opening the feelers can be adjusted against oppositewalls of the opening and by referring to the indicator and scalesheretofore mentioned, the exact distance between said opposite walls canbe accurately determined.

Having described the invention, I claim:

1. A micrometer comprising a circular-shaped head, a handle arrangedcentrally of said head, oppositely arranged feelers slidably supportedby said head, a shaft journaled to said handle and extending into thehead, a finger piece rotatably supported by the handle and detachablysecured to the shaft for rotating the latter in opposite directions,discs secured to said shaft and arranged in spaced relation and havingspirally formed threads upon opposing faces thereof and the threads ofone disc being of right hand formation and the threads of the other discbeing of left hand formation, feeler supporting elements having threadsmatching the threads of said discs and having the feelers removablysecured thereto, and supporting plates removably secured to 55 the headand engaging the feeler supporting elements.

2. A micrometer comprising a circular-shaped head, a handle arrangedcentrally of said head, oppositely arranged feelers slidably supportedby said head, a shaft journaled to said handle and extending into thehead, a finger piece rotatably supported by the handle and detachablysecured to the shaft for rotating the latter in opposite directions,discs secured to said shaft and arranged in spaced relation and havingspirally formed threads upon opposing faces thereof and the threads ofone disc being of right hand formation and the threads of the other discbeing of left hand formation, feeler supporting elements having threadsmatching the threads of said discs and having the feelers removablysecured thereto, supporting plates removably secured to the head andengaging the feeler supporting elements, a scale arranged on the fingerpiece, a marking arranged on the handle for cooperation with the scaleof. the finger piece, a second scale arranged on the handle adjacentsaid marking, and an indicator threaded to said shaft and operating inconjunction with the second-named scale.

EDWARD L. PILLISCHAFSKE.

